Question involving capacitance.

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In summary, a circuit using a neon lamp with a threshold voltage V0 for conduction can store electrical energy in a capacitor, which can be released to flash the lamp. The ratio of energy emitted by the neon flash to a typical 100W light bulb turned on for the same amount of time is 1.62x10^-4J. To find the discharge time of the capacitor, you can use the relevant equations to calculate the time it takes to charge the capacitor from 0 to V0.
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allenli
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A circuit uses a neon lamp. The neon lamp has a threshold voltage V0 for conduction, because no current flows until the neon gas in the tube is ionized by a sufficiently strong electric field. Once the threshold voltage is exceeded, the lamp has negligible resistance.

The capacitor stores electrical energy, which can be released to flash the lamp. Assume that C = 4.00×10^-8 F, R = 1.4200×10^6 Ω, V0 = 90.00 V and ε = 110.0 V.

The 110 V is connected to R and C in series and the neon lamp is in parallel with C.

Question: A typical light bulb emits at 100W. What is the ratio of energy emitted by the neon flash to the light bulb (Assuming the light bulb is turned on for the same amount of time as the neon bulb)?

Through my previous calculations I determined that the amount of energy released by a flash of light is 1.62x10^-4J. How do I attain time to answer the above question?
 
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Hello Allen, and welcome to PF. Please do use the template. What previous calculations led you to 1.62x10-4 J ? (don't bother, I can tell).
Now, since the wording 'negligible resistance' doesn't help you in finding a discharge time for the capacitor, perhaps you are supposed to look at the charging time. That's where the 2.) relevant equations of the template comes in so nicely: do you have something at hand to calculate how long it takes to charge the capacitor from 0 ('negligible resistance' !) to V0 ?
 

FAQ: Question involving capacitance.

1. What is capacitance?

Capacitance is the measure of an object's ability to store an electrical charge. It is defined as the ratio of the electric charge stored on an object to the potential difference across the object.

2. How is capacitance measured?

Capacitance is measured in units called farads (F). It can be measured using a device called a capacitor, which consists of two conductive plates separated by an insulating material known as a dielectric. The capacitance of a capacitor can be calculated by dividing the charge stored on one plate by the potential difference between the two plates.

3. What factors affect capacitance?

The capacitance of an object is affected by several factors, including the distance between the two conductive plates, the surface area of the plates, and the type of dielectric material used. Capacitance also increases as the potential difference across the plates increases.

4. How is capacitance used in everyday life?

Capacitance plays an important role in many modern technologies. It is used in electronic circuit design to store energy and filter out unwanted signals. Capacitors are also used in power grids to regulate voltage, in touch screens to detect touch, and in cameras to store electric charge from light sensors.

5. What are some practical applications of capacitance in science?

Capacitance has many practical applications in various fields of science, including physics, chemistry, and biology. It is used to study the electrical properties of materials, to measure the dielectric properties of liquids and solids, and to study the properties of cell membranes in biological systems. Capacitance is also used in medical devices such as pacemakers and defibrillators.

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